Train-control apparatus



March 1 1927.

T. E. CLARK TRAIN CONTROL APPARATUS ATTORNEY.

m T m V m Filed April 16, 1925 Patented Mar. 1, 1927.

' UNITED STATES PATENT OFFICE.

THOMAS E. CLARK, OF DETROIT, MICHIGAN, ASSIGNOR TO CONTINUOUS TRAIN CON- TROL CORPORATION, OF DETROIT, MICHIGAN, A CORPORATION OF MICHIGAN.

TRAIN -CONTROL APPARATUS.

- Application filed April 16', 1925. semu No. 23,514.

This invention relates to installations for controlling the operation of railway trams by means of ated in the track rails, which'currents pro: uce zones of strong induced currents or induction just in front of the pilot or other leading axle of a vehicle approach ng the int Where the mechanisms, for propagating these high-frequency currents are attached tothe rails.

It further consists in a system for operating waysidesignal lamps to indicate the condition of the track ahead, the track being divided into blocks and the signals being positioned at the junctures of the several blocks to indicate Whetherclear, caution or danger conditions exist in the blocks in advance, and each installation influencing the installation next in the rear, and eachinstallation at the exit end of each block being influenced by the locomotive or other vehicle, if any, in said block, means being provided for propagating high-frequency currents in the rails of any occupied block if the next or second block in advance is occupied, and other means being provided to revent such propagation unless the block is occupied and if the next two blocks 1n advance are unoccupied.

It also consists in novel means on the locomotive, or other desired vehicle running on the track rails, for causing the application of the brakes whenever the vehicles passes over that portion of the track in which the high-frequency current is being propagated, together with means, in-

cluding a current source, by which such brake application may be forestalled by the person in charge of such vehicle. It also 4 consists in the details of construction illustrated in the accompanying drawing and particularly pointed out in the claims. 1

In the drawing, Figs. 1, 2 and 3 are diagrams of transmitting and transforming installations combined with signal installations, the parts being in three different. positions, Figs. land 3 also showing diagrams of receiving devices adapted to be mounted on locomotives or other vehicles equipped with air brakes. Fig. 4 is a detail diagram of a transforming-transmission device. Fig.

5 is a detail diagram of a signal.

Similar reference characters refer to like high-frequency currents propa parts throughout the several views. The

system here presented is for a track on which trains run in only one direction that is from left'to right in the drawing and the diagrams or the transmitting stations are indicated by the letters B, C and D,

station A in advance being understood. 60

The track is divided into blocks at the points 1 and the rails are lettered 2 and 3 2 and 3 etc. Locomotives T are indicated in the blocks B and D adjacent the exit ends of these blocks, and an approach lighting 65 signal stand is positioned at each dividing point 1, these stands each comprising three lamps, a green lamp G to indicate clear conditions inthe adjacent block ahead, a yellow lamp Y to indicate caution conditions in the adjacent block ahead, and a red lamp R to indicate danger conditions in the adjacent block ahead. When a block is entered by a locomotive and the block in advance is occupied, a red lamp will be visible at the exit end of the block being entered. When the first block in advance is unoccupied and the second block is occupied,

a yellow lamp will be visible at the exit end of the block entered, while if neither the next or second block are occupied, the green lamp will be seen.

A transmitter of high-frequency current at the exit end of each block propagates such current in the rails of that block whenever that block is entered and when either a red or yellow lamp is visible at the exit end. A strong induced field moves along the entered block just in front of the locomotive toward the connection to the trans- 9 mitting installation for high-frequency current, and instrumentalitieson the locomotive are so affected by this induced current that the brakes will be set unless forestalled by proper manually operable mechanism on the locomotive. As this induced current is picked up some distance from the exit end of the block in which this current is received, and while the propersignal lamp is plainly visible, the engineer may be depended upon to act accordingly. But should e be incapacitated or fail to heed the signal at the exit end of the block wherein these induced currents are picked up, the brakes will be applied and the locomotive brought to astop.

As the signal system shown in the drawing will function independently of the train control system, it will be first explained. Each installation or station has a track battery 4 which connects to the rails at the entrance of its block by means of wires 5 and 6, a resistance 7 being provided to protect the battery from damage when shorted by a train. A neutral relay 8 at the exit end of the block is connected to these same rails by means of the wires 9 and 10 so that when the block is occupied, this relay is short circuited or de-energized.

The signal and control battery 12 of each station is connected to a polar neutral relay 13 of the next station in the rear. When the two blocks in advance of any station are unoccupied, as we suppose is the case with block. B, relays 8 and 13 of station A are energized, and current from battery 12 flows over wire 16, armature 13 wire 14, relay 13, wire 15*, armature 8 of station A, wire 20, armature 13? and wires 21, 22 and 23 to the battery. This causes armatures 13" and 13 of station B to swing to the right. When the block in advance is occupied, the relay 8 of that block is de-energized, as at station B, and no current passes over wires 14 and 15 to relay 13 of station C. Current from battery 12 passes over wire 16, armature 13*, wire 20, armature 8 Wire 15 to relay 13 and then over wire 14, armature 13", and wires 22 and 23 to the battery. Or, negative current from battery 12 may be said to pass over this circuit to cause armatures 13 and 13 to swing counter-clock-wise. As the locomotive T is in block B, the relay 8 of that block is short circuited. Current now flows from the battery 12 of block B over wire 16, armature 13, wire 17, arma ture 13, and wire 18 to lamp G, thence over common wire 19 to armature 8, wire 20, armature 13",and wires 21, 22 and 23 back to the batter As block is not occupied the circuit to its relay 8 is not short circuited and no light will be visible at the exit end of this block C. But if this block were occupied and the relay 8 short circuited so its armatures a and b enga ed their back contacts, current would woul also flow over wires 23 and 24 to. red lamp R, and thence over wire .19, armature 8", wire 20, armature 1,3 and wire 16 back to the battery. This red lam would indicate a danger condition in bloc B, which would be correct as the locomotive T is in that block.

As stated, negative current passes over wire 14 to rela 13 of station D because of the locomotive T in block B. Current will iflow from the battery 12 of station D over wire 16, armature 13, wire 17 armature 13 and wire 25 to lamp Y, indicatin caution and showing that t e second blocl r (B) in advance is occupied. This lamp Y shows because this block D is occupied, and therefore the circuit which includes the wires 14 and 15 is open at armature 8".

At each signal station a transformertransmitter of control current is so connected that it is energized by the main battery 12 of that station whenever that block is occupied, excepting when a green lamp G shows at that station. These transmitting devices are marked 30 and current is conducted thereto at each station from the wire 16 by the Wire31. The wire 32 therefrom is open when the adjacent relay 8 is energized. Referring to Fig. 3, it will be noticedthat the locomotive T has short circuited the relay 8 so that its armature 8 connects the wire 32 to the wires 33 and 34. But the relay 13 is positively energized so that the armature 13 is elevated and the armature 13 is swun clockwise, resulting in an open circuit to the transmitter at both of these points. Therefore," so long as this green lamp is energized, or so long as clear conditions exist in the block ahead, the transmitter 30 will be inoperative.

The conditions in station C are for danger but as block C is not occupied, the transmitter 30 of station C is not energized.

But if the block were occupied, the armature 8 would close the circuit comprising wire 32, armature 8, wire 33, armature 13 and wires 21, 22 and 23 to the battery.

As block D is occupied and as the conditions in station D are for caution, the circuit from the transmitter is over wire 32, armature 8', wires 33 and 34, armature 13 and wires 24 and 23 to the battery. The transmitter is therefore ener ized for both -danger and caution con itions but no control current is propagated in the rails when the conditions at the adjacent station are for clear.

I have shown the details of the transmitter diagrammatically in Fig. 4. A dynamotor 40, or rotary transformer, receives battery current over the wires 31 and 32, and delivers an alternating current of about .07 amperes and 300 to 500 volts over the wires 41 and 42. The filament 43 of the electron tube 44 connects to the wire 31 by means of the wire 45 and an adjustable resistance 46 and connects to the wires 32 and 42 by the wire 47. The wire 41 connects to the plate coil 48 and to the tuning condenser 49, shuntmg the plate coil, and both the coil and condenser connect to plate 50. The wire 42 connects to the grid coil 52, and that connects to the grid condenser 53 and grid leak 54. A wire 56 connects the grid coil and grid leak to the grid 57 of the tube 44. An outplut C011 58 connects to the rails by mans of t e wires 59 and 60 and 9 and 10, a tuning condenser 61 being inserted in one of these wires to prevent the track battery 4 from being shorted by this output coil; The our- -.to 6000 meters wave length rent delivered to the rails may be of any de sired frequency and wave, len th, from 1500 eing feasible.

Mounted in each locomotive is a collectorcoil which connects to the high-frequency relay 72 of the type shown by my co-pending application, Ser. No. 335,941 filed Nov. 5, 1919, by means of. the wires 73 and 74, in one of which is connected a variable condenser 71 whereby this circuit of the relay 72 may be tuned to resonance with the train control current in the rails, and the current induced thereby is picked up by the coil 70. When this relay is thus energized, it opens the circuit shown in Fig. 3 from the battery 75 over wire 76, stick relay 77, wire 78, armature 7 Wire 79, armature 72" and wire to the battery. So long as this cir cuit exists, current will also flow from the wire 76 over Wire 81 to the solenoid 82 and thence over wires 83 and 84 to the wire 78. The energized solenoid 82 holds the valve 85, attached'to the stem 86, on its seat and prevents the escape of air from the train line 87.

Whenever the locomotive moves into that portion of the track wherein the high-frequency current propagated by a transmitter 30 is suflicient to produce an induced current of suflicient power in the circuit of the relay 72 to swing its armature 7 2 to the position shown in Fig. 1, the circuits to therelay 77 and to the solenoid 82 will be opened, resulting in the valve 85 leaving its seat and air escaping from the train pipe 87. If this valve 85 remains in this position for a predetermined period of time, the air pressure in the train line or pipe will be sufficiently reduced to cause the brakes to operate. a i

In order to permit the engineer to forestall this application, a key is provided, connecting to the wire 84, and adapted to be pressed to engage the contact 91 connecting to the wire 80. This engagement will close the circuits to the relay 77 and solenoid 82 and cause the valve 85 to be moved back to its seat where it will remain until the locomotive enters another section of track carrying this high-frequency current.

Each of these signal and control stations is operated by a storage battery 12 which functions to energize the relay 13 of the next block in the rear when such block is unoccupied; which supplies current to a signal lamp at that station when the block in the rear is occupied; and which supplies current to the transformer-transmitter 30 of that block when that block is occupied. As the lamp and transmitter require current only when the block is occupied, this system is especially adapted for railways having few trains. -The length of track which will be sufliciently impressed with the high-frequency control current will depend upon motive to operate.

the character of the electron tubes employed, but a few hundred feet at the exit end of each block willusually be sufficient to permit the receiving installation on the loco- As the signal lamp at the end of the block will be in plain view from-the locomotive before the instrumentalities on the locomotive begin to function, the engineer will have ample time to depress the key 90 and to forestall the opening of the valve 85. It is to be understood that so long as the engineer is in full control ofhis faculties, the instrumentalities on the locomotive can be prevented by him from operating, but should he become incapacitated for any reason whatever, the brakes will be applied at the entrances of the cantion and danger "blocks. The insulations' that when the word locomotive is used it is intended to include any kind of automotive vehicle equipped with air brakes.

The currents from the transformers 30 may be superimposed on the currents from the track batteries 4 without either current being affected. The details of construction and the proportions of the parts may all be changed by those skilled in the art without departing from the spirit of my invention as set forth in the following claims.

I claim:

1. In a train signal and control system adapted for use in connection with a track divided into blocks, the combination of a source of direct current for eaclrblock, a

signal installation embodying three lamps at the exit end of each block, means controlled by the presence of a vehicle in any block to cause. current to pass from the current source to one of said lamps according as the first or second block in advance is occupied or both are unoccupied, means at each block to transform said direct current into highfrequency current and to propagate such high-frequency current in the rails of said block, and means controlled by the' adjacent signal installation ,to determine the operation of the transformer.

2. In a train control system adapted for use in connection with a track divided into blocks, normally inoperative installations at each block to propagate high-frequency current in the rails thereof, and a pair of control devices to jointly cause the operation of open circuit between the current source and,

said tube embodying two relay armatures, one of said armatures moving to circuit closin position when the block to which its insta lation is connected is occupied and the other armature moving to circuit closing osition when either of the next two blocks in advance is occupied. v

4. In a train control system adapted for use in connection with a track dividedinto blocks, a normally ino era-ti e installation ior each block and a apted to propagate high-frequency current therein, means operative when the block to which the installation is connected and either the next or the second block in advance are both occupied to cause the operation of such installation, a vehicle and an installation thereon comprising a current source, an electrical circuit, and an electromechanical brake valve which is kept closed when the circuit between it lected to open said circuit to the valve and ermit the valve to open when such current is collected.

5. In a train signal and control system adapted for use in connection with a track divided into blocks, the combination of a signal installation at the exit end of a block embodying a lamp to indicate the occupancy of the track ahead, normall inoperative means at the exit end of said block to propagate high-frequenty current in the rails of said block, a track battery at the entrance end of said block and a track relay at the opposite end connected to the rails thereof, a current source and a normally 0 n circuit between the current source and t e lamp.

installation and the high-frequency propagating means of said block, an armature for said track relay constituting a part of said last named circuit and adapted to move to circuit closing position when the block is occupied, and a relay embodying an arms ture constituting a part of said last named circuit and adapted to be moved to circuit closing position when the block in advance is occupied.

THOMAS E. CLARK. 

